Finish the following sentences according to the text.

1) A dam is a barrier across flowing water that ….

2) Dams may be classified according to ….

3) The selection of the type of a dam for the site is a problem in ….

4) Feasibility is governed by ….

5) According to height, there are ….

6) A dam must be capable of ….

7) The material underlying a dam must be capable of ….

Decide whether the following statements are true or false according to the text.

1) A dam is a barrier across flowing water that obstructs, directs or retards the flow, without creating a reservoir, lake or impoundment.

2) Topography, geology and climate govern the engineering feasibility and cost.

3) A low dam is more then 30 m high and a medium-height dam is less 100 m then high but more then 30 m high; and a high dam is over 100 m high.

4) The height of a dam is defined as the difference in elevation between spillway crest and the highest part of the excavated foundation.

5) Gravity is the weight of a dam which is the product of its volume and the specific weight of the material.

6) Ice pressure is exerted on the downstream face of a dam.

7) Most failures of dams have been caused by failure of the foundation.

8) Construction of dams and reservoirs requires the closest cooperation of different specialists in order to ensure a maximum degree of safety of the dams.

Answer the following questions.

1) What is a dam?

2) How may dams be classified?

3) What is a spillway?

4) What are the types of dams?

5) How is the height of a dam defined?

6) Why are dams built?

7) Dams provide head for generating hydroelectric power, don’t they?

8) Does a dam protect against flooding from rivers and the seas?

9) Must a dam be relatively impervious to water?

10) What forces must a dam be capable of resisting?

11) Must a dam be relatively impervious to water?

12) What forces must a dam be capable of resisting?

13) What must the material underlying a dam be capable of?

14) What has been caused by failure of the underlying material?

15) What does the construction of dams and reservoirs require? Why?

Fill in the table according to the text.

Make a plan of the text.

Choose the best title to the text. Explain your choice. You may propose your own title.

a) Dams.

b) Construction of dams.

c) Forces acting on dams.

d) Dam classification.

e) Main features of dams.

Make a summary of the text.

Try to find any additional information about dam classifications and forces acting on dams.

Choose the best synonym to the given words.

a) to create – to destroy, to build up, to originate, to break

b) to retard – to prevent, to speed, to delay, to quicken

c) to protect – to look after, to shelter, to defend, to care for, to attack

d) to assure – to promise, to guarantee, to ensure, to insure

e) to increase – to mount, to drop, to grow, to decrease

f) selection – collection, choice, variety, range

g) consumption – use, expenditure, conservation, spending, utilization

h) relative – absolute, relation, corresponding, utilization

Build up the correct words.

Model: amd → dam

Fill in the correct prepositions, then choose any four items and make sentences.

1) according ___sth.; 2) to be subdivided ___ sth.; 3) to depend ___ sth.; 4) to define ___ sth.; 5) to provide ___ sth. ___ generating power; 6) to protect ___ sth.; 7) to be impervious ___ water; 8) to act ___ a dam; 9) water ___ pressure; 10) to be capable ___ sth.

Find the translation of the following terms and memorize their meaning.

Read the title of the text. What is the text about?

While reading the following text, find the synonyms to the words in the left column of the table, answer the following questions.

a) Does a dam stop the flow of water?

b) Does a dam change the water level in the reservoir?

c) What is the stored water used for?

Text B                                                       What does a dam do?

Decide whether the following sentences are true or false according to the text.

1) A dam stops the flow of water and creates a lake or reservoir below it.

2) The stored water is used for irrigation, water supplies and etc.

3) The stored water is never used to generate electric power.

4) Released water provides river navigation throughout the year.

5) Water usually overflows riverbanks.

6) Lakes and reservoirs increase soil erosion.

Continue the list of what water, reservoirs and lakes, dams do.

DAMS stop the flow of water, create reservoirs and …, store …, …

RESERVOIRS AND LAKES provide …, …

WATER is used for...

21. Get ready to speak about “What does a dam do?”

Find the translation of the following terms and memorize their meaning.

Read the title of the text. What can this text deal with? Read the text and answer the following questions.

a) Are embankment dams also known as fill dams?

b) What are three main kinds of masonry dams?